Influence of structural parameters on the static performance of self-inductive radial displacement sensor

Abstract

The self-inductive displacement sensor has been widely used in active magnetic bearing systems for its excellent performance. However, there is a lack of studies on this sensor’s output characteristics according to the voltages directly from the coils, not from the processing circuit. Therefore, it needs to be further studied to improve the sensor theory and provide technical guidance for the sensor design. This paper analyzed the sensor’s working principle and designed some radial sensors with different nominal air gaps and coil turns. Then the effects of the nominal air gap and coil turns on the sensor coil’s output voltage and sensitivity were studied through the finite element simulation and experiments. According to the results, the number of coil turns could hardly affect the sensor’s static output voltage and sensitivity. The sensor sensitivity in the linear measurement range is proportional to the reciprocal of the nominal air gap length, but it is much less than the theoretical value. The results of this paper provide a valuable reference for the theoretical analysis and structural design of the self-inductive displacement sensor.